The invention relates to a method for producing a penetrator having a penetrator core composed of a tungsten heavy metal (THM) with a high fraction of tungsten and an exterior sheath composed of a material that is more ductile compared to the penetrator core.
Penetrators composed of a tungsten heavy metal alloy generally have a high fraction of tungsten (90 to approximately 97 wt.-%) because, due to their high mass, these materials have good penetration performance with vertical impact on simple armored targets. However, the high tungsten fraction causes brittleness in the material such that, in the case of oblique targets or multi-plate targets, the penetrator often breaks, even before penetrating the target. As a rule, due to their low mass, the kinetic energy of the relatively short broken pieces that result is not sufficient to penetrate the remaining target plate(s).
The brittleness of known THM penetrators frequently increases by virtue of the fact that, during mechanical processing, for example, during turning or grinding, cracks occur in the tungsten grains near the surface, which then may lead to an early failure of the penetrator in question due to the spreading of the cracks.
DE 41 13 177 C2 discloses removing the outer tungsten layers in the geometry of the finished penetrator by etching in order to increase the stability of mechanically processed penetrators. It has actually been shown that such an etching off of the exterior tungsten layers causes a considerable increase (i.e., up to 20%) in the impact value of the respective penetrator.
However, the known method has the disadvantage that acids must be used that are harmful to the application and to the environment. Moreover, the production of such penetrators is relatively labor intensive because the predetermined mass of the penetrator may not be influenced by the etching process.
Furthermore, DE 40 16 051 C2 discloses a penetrator in which a breakable penetrator core composed, for example, of tungsten heavy metal, is protected by a ductile shell. For this purpose, the ductile shell, composed, for example, of steel, is applied with a positive fit to the tungsten core by roller spinning. This known method is also relatively costly and time consuming.